Philadelphia (Ph+) positive leukaemias are an example of haematological malignant diseases where
different chromosomal rearrangements involving both BCR and ABL1 genes generate a variety of chimeric
proteins (BCR/ABL1 p210, p190 and p230) which are considered pathological “biomarkers”. In addition to
these three, there is a variety of fusion transcripts whose origin may depend either on diverse genetic
rearrangement or on alternative/atypical splicing of the main mRNAs or on the occurrence of single-point
mutations. Although the therapy of Ph+ leukaemias based on Imatinib represents a triumph of medicine, not all
patients benefit from such drug and may show resistance and intolerance. Furthermore, interruption of Imatinib
administration is often followed by clinical relapse, suggesting a failure in the eradication of residual leukaemic
stem cells. Therefore, while the targeted therapy is searching for new and implemented pharmacological
inhibitors covering all the possible mutations in the kinase domain, there is urge to identify alternative
molecular targets to develop other specific and effective therapeutic approaches.
In this review we discuss the importance of recent advances based on the discovery of novel BCR/ABL1
variants and their potential role as new targets/biomarkers of Ph+ leukaemias in the light of the current
therapeutic trends. The limits of the pharmacological inhibitors used for treating the disease can be overcome
by considering other targets than the kinase enzyme. Our evaluations highlight the potential of alternative
perspectives in the therapy of Ph+ leukaemias.